Control dial assembly



March 16, 1948. A. H. GERHARDT ET AL. 2,433,045

CONTROL DIAL ASSEMBLY Filed Nov. 1, 1946 .2 Sheets-Sheet 1 March 1948. A. H, GERHARDT El AL 2,433,045

CONTROL DIAL ASSEMBLY Filed NOV. 1, 1946 2 Sheets-Sheet 2 Patented Mar. 16, 1948 CONTROL DIAL ASSEMBLY Andrew H. Gerhardt, Skokie, and Arthur P.

Schulz, HinsdalepIlL, assignors to Thor Corporation, a corporation of Illinois Application November 1, 1946, Serial No. 707,054

1 20 Claims.

The present invention relates to manually controlled devices for adjusting various apparatus, such as a multiple switch for selectively controlling the operation of various mechanisms. A control of the type embodying the present invention, is adaptable to a wide field of use, and is herein illustrated in conjunction with a convertible clothes and dishwashing machine.

When the machine is used for washing clothes, the control may be moved from its corresponding off position to either of the two other positions, namely wash or dry at which the control completes certain electrical circuits for actuating mechanisms for effecting respectively a clothes Washing operation or a drying operation.

When the machine is converted for use as a dishwashing machine, the control is initially adjusted so as to be in registration with the corresponding off position, and is then subsequently moved to either of its other two positions of adjustment, namely wash and dry, at which the control completes proper electrical circuits for operating the mechanisms in carrying out the dishwashing and drying operations respectively.

The control is constructed and arranged so as to permit only single step-by-step adjustment. that is from one position to the next successive position, and a slight time delay takes place at each position of adjustment before the control can be adjusted to still another or its former position of adjustment. This delay action is of par.- ticular importance for control mechanisms wherein it is necessary that certain mechanisms or the electrical motor desirably should come to rest before another operation is initiated, for example where two selective drive mechanisms are adapted to be independently operated at different times, by the same motor rotating in opposite directions. For such a. condition time delay action is a highly important factor in order to be certain that the motor comes to complete rest, before different electrical circuits are completed and energized for driving the motor in the opposite direction. This is so, because the motor upon a mere change in adjustment of the control, might continue to operate in the same direction as it previously operated, and would not cause the desired mechanism to function as required, or might cause damage to certain mechanisms which are capable of being actuated only when the motor rotates in a certain direction.

One of the objects of this invention is to provide a novel manual control device of the character indicated, which insures a time delay incident to adjustment of the control to successive positions or stations.

Another object is to providea novel control device constructed and arranged so as to insure against improper operation of different mechanisms of the apparatus, wherein several separate functions or operations are to be performed by the apparatus.

A further object is to provide an improved manual control device for apparatus, wherein several functions and operations are to be performed, preferably in a predetermined sequence, and which control is constructed and arranged so as to insure that the control is arrested and proper electrical circuits broken and others completed each time the control is moved to a successive position or station of adjustment.

Still another object is to provide a novel control of the character indicated, which is positive in operation, durable in use, and capable of being economically manufactured.

Other objects and advantages of this invention will be apparent from the following description, taken in connection with the accompanying drawings in which:

Fig. 1 is a face view of a convertible clothes and dishwashing machine, provided with a control device embodying the present invention.

Fig. 2 is an enlarged vertical sectional view through the front wall of the machine and control device, taken substantially as indicated at lines 2-2 on Fig. 1.

Fig. 3 is an enlarged vertical axial section through the control knob assembly and housing, taken substantially as indicated at line 33 on Fig. 1. n

Fig. 4 is an enlarged face view of the control knob assembly and housing.

Fig. 5 is a rear view of the housing per se.

Fig. 6 is a vertical sectional view through the housing, taken substantially as indicated at line 6-8 on Fig. 5.

Fig. '7 is an enlarged rear elevational view of the knob and housing assembly.

Fig. 7a is a fragmentary view of co-operating stop features of the knob and housing for limiting rotary movement of the knob.

Fig. 8 is a vertical sectional view, taken substantially as indicated at lines 8-8 on Fig. 7. and showing the knob in process of being adjusted.

Figs. 9, l0 and 11 are side elevational, face and rear end views respectively of the control knob element.

Fig. 12 is an enlarged fragmentary cross sectional view, taken substantially as indicatedat lines l2--l2 on Fig. 8, showing the position of adjustment of the detent. means during the initial portion of movement of the knob, preparatory to readjustment.

Fig. 13 is a sectional view similar to Fig. 12, showing the normal position of adjustment of the detent means, when the knob is disposed at oneof its positions or stations of adjustment.

Fig. 14 is a sectional view similar to Fig. 12, showing the position of the detent means incident to rotation of the knob in opposite direction for readjustment.

Fig. 15 is a sectional view similar to Fig. 12, showing the detent means in an operative position for blocking further movement of the knob, when it has been moved from one position to the next successive position of adjustment.

Fig. 16 is a staggered, fragmentary sectional view, taken substantially as [6-46 on Fig. 8. 1 V

The control device embodying the presentinvention is illustrated as used in conjunction'with a cabinet type, convertible clothes and dishwashing machine, indicated generally at l0, having a sheet metal external cabinet I I. vice includes a shell-like housing I2, preferably formed as a casting rigidly attached to the outer front wall of the casing. ll of the machine, by means of a air of screws I4 threaded into bosses indicated at lines The control de- I5, formed integrally with the interior, of the housing. Secured to a pair of vertically aligned centrally disposed bosses l8, formed integrally with the interior of the housing by means of a pair of screws [9, is a mounting plate 20 of generally rectangular form, as seen in Fig. '7 of the drawing. Rigidly mounted in said plate, substantially centrally of the housing, is a bearing 22 in which is journalled a shaft 24, the forward portion of which is enlarged, forming a shoulderadapted to a butt against the adjacent end of the .bearing 22. The opposite end of the shaft is reduced in cross sectional dimensions, and has rigidly mounted thereon a sprocket wheel 26.

A control knob is telescopically splined on the forward end portion of the shaft 24. As shown, said portion of the shaft is of hexagonal cross section and is telescoped into a hexagonal bore of a boss 3| in the knob, as seen in Fig. 11 of the drawings.

When the knob 30 is rotatably adjusted, shaft 24 is correspondingly rotated, together with the sprocket wheel 26. As shown in the drawings, the sprocket wheel is interconnected with a second sprocket wheel 35, positioned exteriorly of the front wall of the cabinet of the machine a substantial distance below the dial assembly. Said sprocket wheel is connected to and serves to actuate a multiple circuit switch device, indicated is preferably enclosed in an elongated sheet metal housing 40, of generally U-shaped cross section with the upper end of said housing 40, engaged and held in position by the dial housing I2, as shown in Figs. 3 and 8 of the drawings, and the lower portion of said housing d6 being rigidly attached to the front wall I! of the cabinet by a screw 4!, engaged in a boss 42, formed interior- 1y of said housing 40 as seen in Fig. 2 of the drawings.

While we have shown a remotely located switch device to be actuated by the control device through a chain drive, it will be manifest that, if desired, said control device ma be directly connected to the switch device or other apparatus to be controlled.

The knob 30 is adapted to be releasably locked with respect to the housing in any one of a multiplicity of angularly related positions of adjustment. The inner end of said knob, which is preferably formed as a casting, is provided with a multiplicity of circumferentially spaced apart radially extending lugs 45, adapted to co-operate with correspondingly formed and located slots 46, providedin a rearwardly extending flange d1, surrounding the opening 48 in face of the housing through which a portion of the knob 30 pro jects, externally of the housing. As may be seen from the drawings, when the knob is adjusted to a desired angular position, all of its lugs 45 are caused to be seated in the aligned notches or slots 46 of the dial housing, The knob is yieldingly and releasably maintained in such adjusted position, with its lugs seated in the slots, by a coil spring 50, mounted within a bore 5! in the forward end of the shaft 24, and reacting against the front or outer end of the knob as may be seen in Figs. 3 and 8 of the drawings. Thus, to rotate the knob, it is necessary that it be axially moved inwardly, against the reaction of the spring 50, to a position such as seen in Fig. 8 of the drawings, so as to disengage the lugs 45 of the knob from the notches or slots 66 of the housing, and at which position said knob is then free to be rotatably adjusted.

To insure quick and easy seating of the lugs 45 in the notches 46 of the housing, when the knob is adjusted to the next successive position, the forward-faces of the lugs are provided at opposite edges with cam surfaces 45a as seen in Figs.

, 10 and 12 to 15 of the drawings. Said cam surtatably, if necessary, to insure proper alignment of the knob in order to permit the lugs 45 to move generally at 36, mounted within the lower porj tion of the machine cabinet. It is to be understood that the multiple control switch is adapted sprocket 35 for causing selective operation of certain mechanisms, such as certain drive mecha-.

fsp'ringifl. H p g j Carried on [th'el mounting plate 20 is detent 'meansto insure arresting of'the knob after rotajtivfe"movement th'ereof to the next successive into-their registered slots, under action of the CI-station or position 'offadjustment. The detent means includes a sheet metal bracket 55, spot nisms, through an electric motor, or electrical 26, we prefer. to employ a, drive from sprocket wheel 26 to the sprocket wheel 35, which comiprises two short strands of chainQs 'l trained around the respective sprocket wheel and the free.

ends of the chains being interconnected .by rods or wires as indicated at 38.

The bottom sprocket wheel 35, together with '7 the drive interconnecting both sprocket wheels.

welded to the mounting plate 20, and having a pair of spaced apart rearwardly extending lugs I 56, provided with slot apertures 51, in which are and due to the small size of the sprocket wheel v member 58.

mounted the reduced end portions of a flat spring I v I An intermediate portion "of the bracket is offset rearwardly, as indicated at 59,

fandprovided with an enlarged aperture for I loosely and freely accommodating a headed pin 6|. The reason for the large sized aperture 60 I isto permit lateral movement of the pin, such asmay be seen in Figs. 12 to 15 inclusive, incident to performing its detent action. The head of the pin co-acts with the flat spring 58, which serves to project the pin 58, inwardly, as-seen in Fig. 13. The detent means is preferablylocated, so that the pin BI is disposed in registration with one of the slots 46 of the housing, and is adapted to be engaged by one of the lugs 45 seated in said slot, when the knob is moved axially inwardly.

When the knob 30 is moved inwardly to the position seen in Fig. 8, preparatory for rotative adjustment, the lug 45 registering with the pin 6| of the detent, first moves said pin outwardly as seen in Fig. 8 of the drawings and upon rotation of the knob in counter-clockwise direction, as seen in Fig. 12, the lug 45 becomes disengaged from said pin, and the pin again returns to the position seen in Fig. 13, at which position it serves as a blocking element for the next successive lug 45 of the knob, and limits rotation of the knob, as clearly seen in Fig. 15 of the drawings. Such movement corresponds to a single step of adjustment of the knob, and the lugs 45 are now in registration with the slots 46, so that when pressure on the knob is released the action of spring 50 projects the knob in outwardly direction with its lugs seated in said slots 46 of the housing, as seen in Fig. 3 of the drawings. When the knob has been pushed in and is rotated in clockwise direction, the action on the detent pin N is reversed, such as may be seen in Fig. 14 of the drawings. Thus, by virtue of the detent means, only single step-by-step adjustment of the knob 30 may be made, and the knob is caused to be arrested at each successive station for a time interval during which th knob is caused to move outwardly with its lugs seating in the alignment slots of the housing, in order to permit the detent pin 6| to become repositioned and thus permit a further readjustment of the knob.

In order to limit the angular extent of rotative adjustment of the knob, in either direction, the rear end of the knob is provided with a pair of inwardly extending stop shoulders 66, in the plane lugs 45, adapted to co-operate with a stop lug 6 pressed out of the mounting plate 20, as clearly seen in the drawings. It is to be understood that when the knob is rotated to its last position of adjustment in either direction, a corresponding one of the respective stop shoulders 66 of the knob abuts against the stop lug 67.

The outer face of the dial housing is provided with a sheet metal dial plate 10, of generally annular form, and formed integrally with the inner marginal edge thereof are a multiplicity of, tines, adapted to be extended through the central knob opening 48 of the housing, and clinched against the bottom of certain of the slots 46, as clearly seen in Figs. 3, 6 and 8 of the drawings. The face of the dial is provided with suitable lndicia as indicated generally at H, one portion of which includes lndicia for designating certain operations of the machine when it is provided with proper parts for use as a clothes Washing machine. The other part of the dial includes suitable inclicia for use in conjunction with a machine when it has been converted for use as a dishwashing machine. The outer end ofthe knob is formed with a generally triangular shaped portion indicated at 75 which constitutes a finger engaging element. The opposit sides of the triangular shaped element merge to substantially form a sharp edge, as indicated at 16, constituting a pointer for registration with the various indicia on the dial plate 10. For convenience in gripping of the finger engaging element, the two converging sides of the finger grip portion are of corrugated formation, as indicated at 18, so as to provide a roughened finger gripping surface.

Although we have herein shown and described a certain preferred embodiment of our invention, manifestly it is capable of modification and rearrangement of parts without departing from the spirit and scope thereof. We do not, therefore,

wish to be understood as limiting this invention to the precise form herein disclosed, except as we may be so limited by the appended claims.

1. A manual control of the character described, comprising a housing, a shaft carried by said housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob operably connected to said shaft for rotating the latter, means for releasably locking the knob, relatively to the housing, at each of said angularly related positions of adjustment of said shaft, and detent means carried by the housing and cooperating with said knob for enabling step-by-step rotary adjustment of the shaft and serving to positively arrest the knob and shaft, incident to rotation thereof, at the next successive position of adjustment thereof.

2. A manual control of the character described. comprising a housing, a shaft carried by said housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob operably connected to said shaft for rotating the latter, interengaging features on said housing and knob for releasably locking the knob, relatively to the housing, at each of said angularly related positions of ad- J'ustment of said shaft, and detent means carried by the housing and cooperating with said knob for enabling step-by-step rotary adjustment of the shaft and serving to positively arrest the knob and shaft, incident to rotation thereof, at the next successive position of adjustment thereof.

3. A manual control of the character described, comprising a housing, a shaft carried by said housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob operably connected to said shaft for rotating the latter, means for releasably locking the knob, relatively to the housing, at each of said angularly related positions of adjustment of said shaft, and detent means carried by the housing and co-operating with said knob, when said knob is out of locking engagement with the housing, for limiting rotation of said knob and shaft at the next successive position of angular adjustment thereof.

4. A manual control of the character described, comprising a housing, a shaft carried by said housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob operably connected to said shaft for rotating the latter, interengaging features on said housing and knob for releasably locking the knob, relatively to the housing, at each of said angularly related positions of adjustment of the shaft, and detent means carried by the housing and co-operating with said locking'features on the knob, when said knob is out'of locking engagement with the housing, for arresting rotation of said knob and shaft at the next successive position of angular adjustment thereof.

7 housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob operably connected to said shaft for rotating the latter, means for releasably locking the knob, relatively to the housing, at each of said angularly related positions of adjustment of said shaft, and detent means carried by the housing and co-operating with said knob for enabling step-by-step rotary adjustment of the shaft and serving to positively arrest the knob and shaft, incident to rotation thereof, in either direction, to the next successive position of adjustment thereof.

6. A manual control of the character described, comprising a housing, a shaft carried by said housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob operably connected to said shaft for rotating the latter, interengaging features on said housing and knob for releasably locking the knob, relatively to the housing, at each of said angularly related positions of adjustment of the shaft, and detent means carried by the housing and .co-operating with said locking features on the knob, when said knob is out of locking engagement with the housing, for arresting rotation of said knob and shaft at the next successive position of angular adjustment in either direction of rotation thereof.

7. A manual control of the character described, comprising a housing, a shaft carried by said housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob telescopically splined on said shaft for rotating the latter,

ly' to the housing, at each of said angularly related positions of adjustment of said shaft, and

spring means for yieldingly maintaining said knob in a locked position of adjustment, and detent means carried by said housing and cooperating with said knob, when the latter is moved out of locking positiOn with respect to said housing, for permitting a single step rotary movement of said knob and shaft to the next successive position of angular adjustment thereof.

8. A manual control of the character described, comprising a housing, a shaft carried by said housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob telescopically splined on said shaft for rotating the latter, means for releasably locking the knob, relatively to the housing, at each of said angularly related positions of adjustment of said shaft, and spring means for yieldingly maintaining said knob in a locked position of adjustment, and detent means carried by said housing and co-operating with said knob, when the latter is moved out of locking position with respect to said housing, for permitting a single step rotary movement of said knob and shaft, in either direction, to the next successive position of angular adjustment thereof.

9. A manual control of the character described, comprising a housing, a shaft carried by said housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to becontrolled. a finger engaging knob telescopically splined on said shaft for rotating the latter, interengaging features on said housing and knob, for releasably locking the knob, relatively to the housing, at each of said angularly related positions of adjustment of said shaft, and springs means for yieldingly maintaining said knob in a locked position of adjustment, and detent means carried by said housing and co-operating with said knob, when the latter is moved out of lockin position with respect to said housing, for permitting a single step rotary movement of said knob and shaft to the next successive position of angular adjustment thereof.

10. A manual control of the character described, comprising a housing, a shaft carried by said housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably'connected to apparatus to be controlled, a finger engaging knob telescopically splined on said shaft for rotating the latter,

means for releasably locking the knob, relatively to the housing, at each of said angularly related positions of adjustment of said shaft, said means comprising a multiplicity of angularly related, circumferentially spaced apart lugs on a peripheral position of the knob and correspondingly spaced slots in the housing, and spring means for yieldingly maintaining said knob in a locked position of adjustment, and detent means carried by said housing and co-operating with said knob, when the latter is moved out of locking position with respect to said housing, for permitting a single step rotary movement of said knob and shaft, in either direction, to the next successive position of angular adjustment thereof.

11. A manual control of the character described, comprising a housing, a shaft carried by said housing and rotatably adjustable to a Pinrality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob telescopically splined on said shaft for rotating the latter, means for releasably locking the knob, relatively to the housing, at each of said angularly related positions of adjustment of said shaft, said means comprising a multiplicity of angularly related, circumferentially spaced apart lugs on a peripheral position of the knob and correspondingly spaced slots in the housing, the opposite edges of said lugs being inclined to constitute cam faces to facilitate seating in locking relation in aligned slots of the housing, and spring means for yieldingly maintaining said knob in a locked position of adjustment, and detent mean carried by said housing and co-operating with said knob, when the latter is moved out of locking position with respect to said housing, for permitting a single step rotary movement of said knob and shaft, in either direction, to the next successive position of angular adjustment thereof.

12. A manual control of the character described, comprising a housing, a shaft carried by said housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob telescopically splined on said shaft for rotating the latter, means for releasably locking the knob, relatively to the housing, at each of said angularly related positions of adjustment of said shaft, said means comprising a multiplicity of angularly related, circumferentially spaced apart lugs on a peripheral position of the knob and correspondingly spaced slots in the housing, and spring means for yieldingly maintaining said knob in a locked position of adjustment, and detent mean carried by said housing and co-operating with the lugs on said knob, when the latter is moved out of locking position with respect to said housing, for permitting a single step rotary movement of said knob and shaft, in either direction, to the next successive position of angular adjustment thereof.

13. A manual control of the character described, comprising a housing, a shaft carried by said housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob operably connected to said shaft for rotating the latter, means for releasably locking the knob, relatively to the housing, at each of said angularly related positions of adjustment of said shaft, detent means carried by the housing and co-operating with said knob for enabling step-by-step rotary adjustment of the shaft and serving to positively arrest the knob and shaft, incident to rotation thereof, in either direction, to the next successive position of adjustment thereof, and co-operating step members on said knob and carried by the housing for arresting rotary adjustment of the knob and shaft, in either direction, at the two end positions of angular adjustment thereof.

14. A manual control of the character described, comprising a housing, a shaft carried by said housing and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob telescopically splined on said shaft for rotating the latter, means for releasably locking the knob, relatively to the housing, at each of said angularly related positions of adjustment of said shaft, and spring means for yieldingly maintaining said knob in a locked position of adjustment, detent means carried by said housing and co-operating with said knob, when the latter is moved out of locking position with respect to said housing, for permitting a single step rotary movement of said knob and shaft, in either direction, to the next successive position of angular adjustment thereof, and cooperating stop members on said knob and carried by the housing for arresting rotary adjustment of the knob and shaft, in either direction, at the two end positions of angular adjustment thereof.

15. A manual control of the character described, comprising a housing, a bracket member mounted in the housing, a shaft journaled in the member and adjustable to a plurality of angularly related positions and adapted to be 801%- nected to apparatus to be controlled, a finger en gaging knob telescopically splined on the for rotating the latter, interengaging features on the knob and housing for releasably locking the knob at each of said positions of adjustment, spring means for yieldingly maintaining the knob in a locked position of adjustment, and detent means carried on the member and co-operating with the interengaging features of the knob, when the latter is moved axially out of locking engagement with the housing, for permitting a single step rotary movement of said knob and shaft, in either direction, to the next successive position of angular adjustment.

16. A manual control of the character described, comprising a housing, a bracket member mounted in the housing, a shaft journaled in the member and adjustable to a plurality of angularly related positions and adapted to be connected to apparatus to be controlled, a finger engaging knob telescopically splined on the shaft for rotating the latter, interengaging features on the knob and housing for releasably locking the knob at each of said positions of adjustment, spring means for yieldingly maintaining the knob in a locked position of adjustment, detent means carried on the member and co-operating with the interengaging features of the knob, when the latter is moved axially out of locking engagement with the housing, for permitting a single step rotary movement of said knob and shaft, in either direction, to the next successive position of angular adjustment, and stop lugs on the knob and member, adapted to be positioned in the plane of permissible engagement, when the knob is moved axially out of locking engagement with the housing, for arresting rotation of the knob and shaft, in either direction at the two end positions of angular adjustment thereof.

17. A manual control of the character described, comprising a housing, a bracket member mounted in the housing, a shaft journaled in the member and adjustable to a plurality of angularly related positions, a sprocket wheel mounted on the inner end of said shaft and adapted to be connected to apparatus to be controlled, a finger engaging knob telescopically splined on the shaft for rotating the latter, interengaging features on the knob and housing for releasably locking the knob at each of said positions of adjustment, spring means for yieldingly maintaining the knob in a locked position of adjustment, and detent means carried on the member and co-operating with the interengaging features of the knob, when the latter is moved axially out of locking engagement with the housing, for permitting a. single step rotary movement of said knob and shaft, in either direction, to the next successive position of angular adjustment,

18. A manual control of the character described, comprising a supporting member, a shaft carried by said member and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob operably connected to said shaft for rotating the latter, means for releasably locking the shaft and knob, relatively to said member, at each of said angularly related positions of adjustment of said shaft, and detent means carried by the member and cooperating with said locking means for enabling step-by-step rotary adjustment of the shaft and serving to positively arrest the knob and shaft, incident to rotation thereof, at the next successive position of adjustment thereof.

19. A manual control of the character described, comprlsing a supporting member, a shaft carried by said member and rotatably adjustable to a plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, a finger engaging knob operably connected to said shaft for rotating the latter, means for releasably locking the shaft and knob, relatively to said member, at each of said angularly related positions of adjustment of said shaft, and detent means carried by the member and co-operating with said locking means, for limiting rotation of said knob and shaft at the next successive position of angular adjustment thereof.

20. A manual control of the character described, comprising a supporting member, a shaft aesaow carried by said member and rotatably adjustable to a. plurality of angularly related positions and adapted to be operably connected to apparatus to be controlled, at finger engaging knob operably connected to said shaft for rotating the latter, means for releasibly locking the shaft and knob, relatively to said member, at each of said angularly related positions of adjustment of said shaft, and detent means carried by the member and co-operating with said locking means for enabling step-by-step rotary adjustment of the shaft and serving to positively arrest the knob and shaft, incident to rotation thereof, in either direction, to the next successive position of ad- Justment thereof.

- ANDREW H. GERHARDT.

ARTHUR P. SCHULZ.

REFERENCES oirnn The following references are of record in the Number Name Date 2,262,707 Stuokenholt Nov, 11, 1941 2,303,011 Weber et a1. Nov. 24, 1942 1,684,148 Ronneberger Sept. 11, 1928 2,339,904 Almquist Jan. 25, 1944 2,214,730 Jefiers Sept. 1'7, 1940 2,348,860 Siedle May 16, 1944 FOREIGN PATENTS Number Country Date 392,154 Great Britain May 9, 1933 

